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81.
《International Journal of Hydrogen Energy》2022,47(3):1499-1515
Dark fermentation (DF) is a promising technology for biohydrogen production. Low efficiency of biohydrogen production is a bottleneck of the scale-up prospects for DF. Additives have been extensively studied to improve the biohydrogen production efficiency. Among of them, iron-based additives present a promising application potential due to their demonstrated significant enhancement of DF efficiency and among the low-cost bioactive agents. However, current reviews mainly examined the effects of nano-materials on DF and an in-depth analysis of enhancing mechanisms with addition of iron-based additives in DF is still lacking. To this end, this article comprehensively reviewed and evaluated the effects of iron-based additives on DF. Further, the potential mechanisms, including altering metabolic pathways, improving activities of microbes and enzymes, promoting electron delivery, and enriching hydrogen-producing bacteria, were discussed. Lastly, prospects and challenges of iron-based additives for subsequent research and large-scale application for DF were summarized. 相似文献
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An anaerobic sludge blanket process, termed the anaerobic baffled reactor (ABR), has been developed and shows promise for industrial wastewater treatment. It combines the advantages of high stability and reliability with a high void volume. The risk of clogging and sludge bed expansion with resulting high microbial losses is reduced and there is no need for special gas collection or biological solids separation systems. Organic loadings as high as 36 g COD l?1day?1 have been achieved with COD removal rates of more than 24 g COD l?1 day?1 and methane production rates exceeding 6 volumes per day per unit volume of reactor. The hypothesis, that the ABR may be adequately modeled as a fixed-film reactor, has been supported. Therefore, a unified approach, based on fundamentals of bacterial kinetics and mass transport, appears useful for modeling this and similar systems. Pilot plant studies are necessary to determine the scaling factors of the system as well as the overall efficiency and costs. 相似文献
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钢渣微粉对牛粪厌氧发酵产沼气的影响 总被引:1,自引:0,他引:1
为提高沼气发酵效率和沼气产量,以不同钢渣微粉作为沼气发酵的功能促进剂,探讨其对牛粪厌氧发酵的沼气产量、发酵前后pH值和发酵前后COD值的影响。结果表明:钢渣微粉对牛粪厌氧发酵产沼气具有显著的促进作用,不仅能够提高原料的累积产气量和产气速率,而且能使产气高峰期大幅提前,其中0.5% ZHB钢渣微粉对牛粪厌氧发酵产沼气效果最佳;钢渣微粉明显提高发酵前各处理组的pH值;钢渣微粉有助于提高厌氧发酵的COD值降低率,其中0.5%的ZHB钢渣微粉总COD值降低率达到64.74%,同时可以促使发酵启动最快,效率最高,周期最短。 相似文献
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Hasina M. Pervin Paul G. Dennis Hui J. Lim Gene W. Tyson Damien J. Batstone Philip L. Bond 《Water research》2013
Temperature-phased anaerobic digestion (TPAD) is an emerging technology that facilitates improved performance and pathogen destruction in anaerobic sewage sludge digestion by optimising conditions for 1) hydrolytic and acidogenic organisms in a first-stage/pre-treatment reactor and then 2) methogenic populations in a second stage reactor. Pre-treatment reactors are typically operated at 55–65 °C and as such select for thermophilic bacterial communities. However, details of key microbial populations in hydrolytic communities and links to functionality are very limited. In this study, experimental thermophilic pre-treatment (TP) and control mesophilic pre-treatment (MP) reactors were operated as first-stages of TPAD systems treating activated sludge for 340 days. The TP system was operated sequentially at 50, 60 and 65 °C, while the MP rector was held at 35 °C for the entire period. The composition of microbial communities associated with the MP and TP pre-treatment reactors was characterised weekly using terminal-restriction fragment length polymorphism (T-RFLP) supported by clone library sequencing of 16S rRNA gene amplicons. The outcomes of this approach were confirmed using 454 pyrosequencing of gene amplicons and fluorescence in-situ hybridisation (FISH). TP associated bacterial communities were dominated by populations affiliated to the Firmicutes, Thermotogae, Proteobacteria and Chloroflexi. In particular there was a progression from Thermotogae to Lutispora and Coprothermobacter and diversity decreased as temperature and hydrolysis performance increased. While change in the composition of TP associated bacterial communities was attributable to temperature, that of MP associated bacterial communities was related to the composition of the incoming feed. This study determined processes driving the dynamics of key microbial populations that are correlated with an enhanced hydrolytic functionality of the TPAD system. 相似文献
89.
干式发酵加温系统中存在着无法根据变工况提供相应的加温方式的问题,为此,针对200m。的车库式干式发酵池,根据不同的天气状况切换空气源热泵单独加温模式与电锅炉.空气源热泵联合加温模式[1],以满足沼气池内的加温需求。还针对最不利工况条件下空气源热泵可能存在的结霜问题,提出相应的除霜方案,保障空气源热泵在最不利工况下的正常运行。实验采取的干式发酵池内设计温度为35℃,原料体积占发酵池的73%,原料中固体占30%,水占70%,发酵池尺寸为12.5m×4m×4m,通过计算得到需要加热盘管总长度为125m。 相似文献
90.
沈阳市污水处理厂污泥处理工程是目前世界上已投入运行的处理规模最大的机械化槽式污泥堆肥项目,介绍了项目工艺流程及设计情况(物料衡算、单体工艺参数、主要设备等),总结了项目设计特点,并分析了项目运行效果,最后得到结论:对于超大型污泥处理项目,堆肥仍可视为有效处理方法之一;规模的扩大不应以牺牲环境质量为代价,除臭仍应受到充分重视;机械化程度的提高对于规模化堆肥技术的推广具有现实意义;该项目堆肥成品含水率为35%,严于国家标准,但并未引起运行成本升高,对于采用返混为主的堆肥系统是一个有益的借鉴;在本土化基础上的国际合作是探索适合中国国情污泥处理处置道路的理想选择. 相似文献